Without Clean Data, Clean Water is at best a lottery. Measuring the
impact of a household water treatment device by surveying often shows 25%
improvements in health even if people don’t regularly use the treatment
device [1]. Objectively measuring the usage of a household water treatment
device can eliminate this 25% bias [2] and give essential information about
which treatment devices work best. Unfortunately the available products to
objectively measure treatment device usage are too complex, precise, and
expensive for our client and partner Pure Home Water.

Pure Home Water (PHW) is a social enterprise and legally registered
non-profit organization based in Tamale, Ghana founded in 2005 by Susan
Murcott, Senior Lecturer in MIT's Department of Civil and Environmental
Engineering. PHW has provided clean water to 100,000 people with their
AfriClay filter. But, how many of these people still use PHW’s filters? What
is an average usage cycle of their water filter like? To be able to serve
its next 100,000 beneficiaries, PHW desperately needs the answer to these
questions.

Our innovation came from a deep understanding of our partner’s need: PHW
needs detailed usage information, but does not need precise information. PHW
would like to know if their filters are used for 5 days, 5 months, or 5
years; all year round or only in the hot season. This information can be
gathered with a usage sensor instead of a flow meter.

Our novel usage sensor counts and records how long the household water
treatment device is used each day and at what times. This means that no part
of the sensor has to come in contact with the clean drinking water and that
a simple switch and interrupt architecture can be used for the data logging
hardware and software. Our measurement technology is applicably beyond just
PHW’s filter to any household water treatment device that uses a
water-cooler type spout.

Ultimately, we hope to see major players in this space, like UNICEF,
begin to use, prioritize, and eventually insist upon the use of objective
measurements of the field-usage of household water treatment devices.